Semiconductor sensors have been designed that include a semiconductor substrate, sensing portions provided over one surface of the semiconductor substrate, and pads provided on the periphery of the sensing portions over the one surface of the semiconductor substrate. In such a semiconductor sensor, bonding wires are electrically connected to the pads. Also, signals from the sensing portions are transmitted through the pads and through the bonding wires. (See e.g., Japanese Patent Application 2003-531017, which relates to U.S. Pat. No. 6,951,824, and Japanese Patent Publication 2002-504026, which relates to U.S. Pat. No. 6,656,368.)
In these prior art semiconductor sensors, a cover member formed of semiconducting material can be provided over one surface of the substrate to protect the sensing portions. This cover member is formed through sacrificial layer etching and multiple film formation processes or by attaching it to a semiconductor substrate with low-melting glass or another suitable adhesive material.
The cover member covers the sensing portions, and yet the cover member is separated from the sensing portions at a distance. Thus, the cover member is unlikely to contact the sensing portions. Also, foreign matter is unlikely to contact the sensing portions. Therefore, the sensing portions are appropriately protected, and sensor characteristics can be maintained.
To maintain electrical connection between the pads and the bonding wires, the cover member covers the sensing portions over one surface of the semiconductor substrate, and the cover is spaced from the pads.
However, these prior art semiconductor sensors have certain disadvantages. First, forming the cover member via sacrificial layer etching and multiple film formation processes can be difficult. Also, an attachment region between the sensing portions and the pads for coupling the cover member is typically provided for coupling the cover member. This attachment is relatively large (e.g., 5 mm) and can undesirably increase the size of the semiconductor sensor. For instance, when the cover member is attached with adhesive material, the attachment region is typically large to allow for possible flow of the adhesive material.